Diesel engine load usually refers to the size of the diesel engine resistance moment. Because the average effective pressure is proportional to the torque, the average effective pressure is used to represent the load. The working condition of the diesel engine is determined by the speed and load. The load characteristic refers to the relationship between the main performance parameters (fuel consumption ratio ge, the consumption gf and the exhaust temperature TR, etc.) which vary with the load when the diesel engine is in constant speed. Since the rotational speed is constant, the effective power can be used as a measure load. In the process of engine commissioning, load characteristics are often used as the standard of performance comparison. In addition, the load characteristic gives the relation between the engine load and the fuel consumption rate under the constant speed condition, so the load can be changed in a large range, and the stationary engine (such as the generator engine) with the constant speed is very important. If the load characteristic curve of a series of different speed is measured from the engine, the most economical working condition of the stationary or transport engine can be selected. Diesel engine in operation, the amount of gas is not changed, mainly by changing the amount of fuel per cycle to change the concentration of the mixture (that is, excess air coefficient), so as to regulate the load of the diesel engine (called Quality Regulation). In other words, the diesel engine is mainly by changing the position of the fuel injection pump adjusting rod, by increasing or reducing the amount of fuel supply to change the load.